CDNGuyYou could probably do it, the straps are attached by spring bars in the back; however, the actual lug width is very small (around 15 mm). The listed lug width is because the attachment of these bracelets is almost integrated, they have a taper where they attach to the case and then flare out. If you were to get a 15mm NATO strap, you could fit it through the lugs but it would likely look very strange.
CDNGuyAlternatively, a quick Google search shows that adapters exist for attaching standard width straps to G-Shock's. Here's one example:
https://countycomm.com/products/adapters-for-casio-g-shock-watches
This specific example may not fit this model, if you would like to attach a NATO to this specific model you may need to find another adapter or some other solution.
CDNGuyI just got NATO adapters for a different Gshock model. The brand I got is jaysandkays, they are on Amazon but they are cheaper on EBAY direct from them. Be careful because its not one size fits all....meaning youll need to find the adapter that will fit your watch model AND select the size of the straps youll use. For example, 3 of my watches are 22mm so I have a way more 22mm straps than anything else. So I ordered the right adapter for my watch and 22mm straps. I do recommend jaysandkays and they have other ways items to use to custom your Gshock.
This specific example may not fit this model, if you would like to attach a NATO to this specific model you may need to find another adapter or some other solution.